Method of producing nitrogen compounds.



C. E. AGKER.

METHOD or PRODUCING NITROGEN COMPOUNDS.

APPLICATION FILED OUT. 27, 1910.

1,018,802. Patented Feb. 27, 1912.

tmirran STATES ATENn OFFICE.

CHARLES E. ACKER, OFOSSINING, NEW YORK, ASS-IGNOR TO THE NITROGEN COMPANY,

A. CORPORATION OF NEW YORK.

METHOD PRODUCING NITROGEN COMPOUNDS.

Specification of Letters Patent.

Application filed October 27, 1910. Serial No. 589,292.

To all whom izimay concern:

Be it known that I, CHARLES E. Ao nn, a citizen of the United States, residing at Ossining, in the county of Westchester and State of New York, have invented certain new and useful Improvements in Methods for Producing Nitrogen Compounds, of which the following is a full, clear, and exact description.

In my United States Patent No. 914,214, dated March 2, 1909, I described a process relating to the electrolytic production of nitrogen compounds, such as nitrids, amids, cyanamids and cyanids of the alkali and alkaline-earth metals. This process comprised the steps of electrolyzing a molten compound of a metal capable of forming nitrogen compounds, alloying the separated metal with a cathode metal, removing the alloy, and reacting on it with a nitrogenous reagent, separating the products of reaction, and returning the residual metal to the cathode. Incidental steps comprised cooling the alloy before treatment with the gas, particularly when ammonia was employed as the nitrogenous reagent. This is of considerable importance, because the ammonia would to a certain extent be decomposed into its elements nitrogen and hydrogen, if injected into the alloy at the same temperature at which the alloy would ordinarily be produced, and this free nitrogen in the case of a sodium-lead alloy would pass through unabsorbed. It is further of importance since the initial product of the reaction between the alkali or alkaline-earth metal and ammonia, would be .an amid, e. 9., sodium amid (Na N11 which, if formed at all at such temperature would quickly decompose,

in which case, in the absence of carbon, the nitrogen would be set free. It was pointed out that sodium amid produced at a rela tively low temperature could subsequently be converted into alkali cyanid or alkali cyanamid, by treating it in the same chamber, but at a higher temperature, with carbon or a carbonaceous reagent, in the presence of the residual metal. Alkali amid and possibly cyanamid (N a CN would thus be produced. as intermediate compounds in the production of the cyanid. Certain specific features relating to the production of these intermediate compounds, and their conversion into final compounds, including the methods of effecting changes in the temperasuch gas would cyanid and so bon electrode serving as ture, were described in my U. S. Patent 914,100, also bearin date of March 2,1909; this latter patent being a division of the original case above referred to. In this patent, I described a method of producing the desired allo by electrolyzing molten sodium chlorid and alloying the liberated sodium with a cathode metal; thereafter conducting the alloy into a reaction chamber containing molten cyanid resting on the surface of the alloy. The reaction chamber was de+ scribed as being heated by means of an alternating current which was passed through the molten products of reaction between a carbon electrode, which extended into the cyanid, and the surface of the alloy or the pot itself; the molten products acting as aliquid resistor. In Patent 914,100, I further stated that ammonia could be introduced directly into the molten alloy, and it will be evident from an examination of the original drawing, Figure2, that unabsorbed portions of pass up through the molten come into contact with the carbon electrodes therein.

I have nowdiscovered that by passing a direct current of electricity from the surface of an alkali-metal alloy, e. 9., sodium-lead alloy, in the reaction chamber, through for example, molten sodium cyanid, to the carcathode, the alkali metal may be liberated in the pure state on the surface of such cathode; and that if ammonia, hydrocarbon amins, their decomosition products or mixtures of any of the foregoing reagents, or other suitable nitrogenous reagent be brought into contact with the surface of this cathode, while the current is passing, such reagent will instantly combine with the liberated alkali metal and car-- bon of the cathode, to form more sodium cyanid; this product being immediately commingled with the mass of molten cyanid previously provided or formed. It should be noted that-in the present method it is unnecessary to bring the ammonia or other nitrogenous reagent directly into contact with the alloy and this is a distinct advantage in that all decomposition of the reagent by contact with the considerable mass of diluent metal, 6. 9., lead, in the alloy is avoided. The reagent may fadvantageously be introduced through a hole or conduit in the carbon cath'ode directly to the surface where the sodium is liberated. Another ad- Pateiited Feb. 2'7, 1912.

I sire particularlyto direct attention to a'class vantage of this process over the earlier patents referred to, lies in the fact that all of the reactions involved in the manufacture of alkali metal cyanid from alkali metals, carbon and ammonia or 'other suitable nitrogenous reagent may be effected atone temperature, and this temperature may be substantially the same as that required to produce the'alloy bythe electrolysis of molten sodium chlorid,of mixed chlorids of sodium and potassium, or-of mixtures of other haloid salts, in connection with a molten metal lic cathode such as lead,.thus permitting the utilization of the alloy as fast as it is produced; economizing energy and permitting the return-of the residual metal to the primary furnace without undue loss of heat.

In the foregoing matter, reference has been made to nitrogenous reagents other than ammoniaand in this connection I deof substances that I have found well adapted for the purpose in question, to wit, hydrocarbon bodies containing nitrogen, obtained from the distillation of vinass'es of the beet sugar refineries, etc., thehydro-carbonamins, such as methylamin, diand trimethylamin, the corresponding ethylamins, and particularly the compoundtrimethylamin (,O H N), or the products resulting from heating to a red heat or-higher, simultaneously with or previous to their use as. a

source of nitrogen, of any of the foregoing hydro-carbons.

WVhen the alkali metal is liberated on the surface of a carbon cathode in an electrolyte consisting of molten alkali cyanid, andjainmo'nia is brought into contact with this carbon, and with .the alkaligmetal at the'moment of its liberation, the conditions are ideal for the complete and rapid absorption of theammonia, and since allof the elements entering into the composition of the alkali metal cyanid are present, the action pro ceeds with great rapidity, and alkali metal cyanid is formed,-the hydrogen of the ammonia escaping, and carrying with-it prac-v tically no uncombined nitrogen or unused ammonia. The hydro-carbon-amins or their breaking down products, or mixtures of any of the foregoing With ammonia may be substituted for ammonia in eifectuating the process.

The temperature most suitable for the production of the alloy through the electrolysis of a molten mixture consisting p'rincipally of' sodium chlorid, may vary'from, 800 down to, say 625 C., and the temperature in the chamber in which the sodium cyanid is produced, in accordance with this process, may be substantially the same. When operating at such temperatures, and understhe conditions named it is a matter of great uncertainty as to just what intermediate reactions actually take place in this process between ammonia, or an amin, e. -g.,'trimethylamin, alkali metal, at the moment of its liberation, and: carbon; the latter element being supplied by the carbon cathode, by the amin, or by the cyanid itselfa body containing carbon.

A notable advantage, useful under cer tain conditions, possessed by the hydro-can bon amins resides in the fact that such bodies contain carbon and henceit is not essential that an additional supply of that element be afiorded. .In fact, in methylamin both nitrogen and carbon are present in the exact proportion required in the cyanid, Whereas in diand trimethylamin the carbon-is 1n excess; the nitrogen present being insuflicient to combine with all of the carbon to form the product sought. In case dior tri-met-hylamin be used therefor as the nitrogenous reagent, nitrogen or some compound, such as ammonia, capable of supplyingadditional nitrogen may bein troduced or. injected into the molten mass in suflicient quantity to make up the deficiency,- A hydro carbon amin e. 9., trimethylamin' may hence beregarded as both a carbonaceous and nitrogenous reagent;

NIL-l-C-l-Na:NaGN-I-H -Inthe U. S. patent to Castner, No. 543,643, July 30, 189 5, the statement occurs with reference to the process described in .said

Patent 541,066, um,-

While the ultimate product is alkali cyanid, several intermediate reactions take place, and these at times render it diflicult to carry on the manufacture without considerable care to avoid loss of nitrogen. I have found by experiment that such loss can be avoided'if I carryon the process in two separate steps, or reactions.

' The first step of the process consisted in passing anhydrous ammonia over metallic sodium, at a temperature between 300 and 400 (3., thereby producing sodium amid,- the reaction being:

NHH Ia:NaNH +H In the second step the sodiumamid is and the previously formed or supplied fused in contact with carbon at a higher temperature, to wit, a dull red heat, whereby sodium cyanid is formed in accordance with the following reaction:

Gastner states in this specification that he was aware that sodium amid had been previously produced in accordance with the lows :671,709, process oftmaking dialkalicyanamid; 682,741, method of making cyanids; 686,949, method of making cyanids; 686,950, method of making cyanamids, all of which relate in one way or another, to the reactions involved in the manufacture of alkali cyanid, or intermediate compounds,

by the treatment of ipreviously or separately made alkali jmeta'l, as described in Castners Patent No. 541,066, with ammonia, etc. A patent was also taken out Ewan and .Pfleger, No. 674,295, May 14, 1901, Process of making alkali amids, which claimed as a novel feature,-the introduction of ammonia down into a mass of alkali metal. With all of these patents, I am familiar, and now wish to strongly differentiate the process disclosed in this specification from all of the above enumerated atents, directing special attention to the act that the sodium, in my process, may be reacted upon with, for example, ammonia, affording nascent nitrogen, and carbon, substantially at the moment of the liberation of the alkali metal by the current on the surface of the cathode; said metal being thus in peculiarly reactive conditione., in the nascent state.

The cathode itself may be of carbon and may, as aforesaid constitute the source ofcarbon; or finely divided carbon may be sus-i pended in the electrolyte; carbon in lump, form or in the form of a hydro carbon gas or oil may be charged into the cyanid; a hydro-carbon amin, or theproducts obtained by heating such amins to a red heator higher may be employed as a source of both nitrogen and carbon; and finally the cyanid itself may, in the absence of free carbon, supplysuch element to the reacting ammonia and alkali metal. the latter case will be dialkalicyanamid and the cyanid electrolyte will itself be gradually reduced to dialkali cyanamid if no free carbon is supplied in the meantime. The

production of dialkalicyanamid would, how'- ,ever, require-a cathode made of material other than carbon.

The product formed in The present process need not be carried 'out'in steps; nor does it require one constituent to be first formed and then reacted with another constitutent at a higher temperature. Further, the operation may with advantage be continuously carried out at a temperature substantially exceeding the melting point of cyanid, (although it may, if desired, be also continuously carried out at the same temperature) and in a separate compartmentof the same apparatus in which the alloy is produced; and the residual alloy or metal may be continuously or intermittent-1y circulated between the two compartments and replenished without substantial change in the temperature.

In my co-pending U. S. application, Serial- No. 575,819, filed Aug. 5, 1910, I described a method of producing alkali and alkalineearth petals by electrolyzing a molten bath cont-ail ing cyanid or cyanamid compounds, in connection with an anode consisting of a molten alloy containing the desired metal; the collected or accumulated metal formed in the apparatus by means of the process therein described being normally run off from such apparatus and separately utilized.

This requireshandling of the metal and involves labor. Each of the metals referred to in that specification may be produced as described;

but. in accordance with the present process, atthe'instant of their liberation by the current and while still in the nascent state, they may be reacted upon with ammonia and carbon, or with other reagents as statede. 9., trimethylamin, the latter preferably with nitrogen or ammonia, to produce cyanids of potassium, sodium, lithium, barium, strontium, or calcium, and'also such Eyanamids of the foregoing metals as are fusible below 900 (1., notably the alkali cyanamids. Mixed cyanids or'cyanamids may be produced in the same way by providing an alloy containing two or more metals which it is desired to convert into mixed cyanids or cyanamid salts.

'VVhen hydrocarbon amins, e. 9., t-rimethylamins are heated 'to a temperature which is apt to be required on the ground of economy such a body does not break up until the instant that it combines with the alkali metal; hence its valuable constituent elements, carbon and nitrogen are also in a nascent state at such instant and a reaction of maximum efiiciency is the result. As previously stated,

some of the hydrocarbon amins contain an excess of carbon over that necessary for the production of cyanids and in order to utilize such excess of carbon while in the nascent state, it is convenient and desirable to introduce simultaneously with the amin a predeterminedquantity of ammonia, the nitrogen'of which will also be liberated in the nascent state and therefore be present in condition to combine/with such excess carbon and the alkali metal to form alkali metal cyanid. ll

In my U. S. application Serial No. 580,190,

filed Sept. 1, 1910, I described a process somewhat resembling that herein set forth,

but with the essential difference that the nitrogen or ammonia in such process reacted directly with a reactive metal carbid instead of with the alkali metal.

In the present process the cathode may be of metal instead ofcarbon, and owing to the heat conducting properties of metal, said cathode may, if desired, be made to serve as a means formaintaining the temperature of the cathode and of the electrolyte in immediate contact therewith, considerably lower than that of the molten alloy beneath.

In the accompanying. drawing I have somewhat diagrammatically illustrated one form of apparatus adapted for carrying out theprocess herein described.

Fig. 1 is a vertical section taken through the respective primary and secondary cells on line I'I of Fig. 2. Fig. 2 is a'plan of the apparatus. Fig. 3 is a detail section of the secondary cathode. Fig. 4- is a bottom view of said cathode.

[ Like reference characters designate like parts throughout the respective views.

Referring to Fig. 1, a suitably lined and covered casing 1 is partitioned into a pr1- mary compartment 2 and a reaction chamber or secondary cell These cells are'.c0nnectedby conduits 4 and 5, so that a body of molten alloy 6 maybe circulated therethrough by a suitable pump 7 Thesuperposed mass of molten cyanidor the like, hereinbeforereferred to is shown at 8. The primary anodes 9 may be of any suitable description; but the-secondary cathode or plunger '10, which may be of carbon or metal, e. 9., cast iron, asabove described, is axially ap'ertured at 11 for the passage of the nitrogenous reagent or reagents therethrough. Such reagents may be gaseous ammonia, trimethylene or the like and pass down through the said aperture to the lower face of the cathode; I prefer to provide a long spiral groove 12 which starts from the opening in the center of the face of the cathode and winds outwardly toward the periphery, so that when-a gaseous reagent is introduced through the hollow shank of the cathode .or plunger, it will be-forced to follow the course of the spiral groove, and thus be made to travel a distance of several feet in contact with alkalimetal, the electrolyte, and the suspended or dissolved material in the electrolyte. The sides of the groove preferably areangularly disposed as shown and form a spiral ridge on the.

face 'ofthe plunger. I have found, when the ammonia is thus made to move or travel along an open bottom groove or conduit in contact with alkali metal, the electrolyte, finely divided suspended carbon in the latter, etc., while continuously submerged in the molten cyanid, that a notable advantage results, in that this procedure permits the introduction and complete reaction'of the ammonia, trimethylamin, etc., far more expeditiously and perfectly than is possible when employing merely a flat cathode surface. v v

If a supplementary nitrogenous reagent such as ammonia be employed in addition to such a reagent as'trimethylamin, it may either be introduced through the -hollow shank of the cathode together with the trimethylami'n, or through a separate pipe 13'. An overflow and withdrawal pipe 14 is pro-- vided for the product, and a vent- 15 for the gas evolved inthe primary cell. Current is led in through-the electrodes 9, passes thence through the molten sodium chlorid 16 or the like, through the molten alloy- 6, molten cyanogen mass 8 and thence out and .di-

through the cathode 10.

The terms direct reaction rectly reacting .as used in the appended' clalms are intended to differentiate from-intermediate or -step-by-step reactions.

In the present process the elements, being for the most-part in the nascent state, immediately and directly react to form the resultant product.-

. The present process may also'be substantially, although not so etficaciously, efiected by liberating the .alkali metal from the-alloy byelectrolyticdeposition, for example, as

described in my application 575,819, above referred to; permitting said metal'to accumulateon the surface of the-cyanidor like electrolyte, and there reacting upon said metal with ammonia, hydrocarbon amine, their decomposition products, (e; g. trimethylamin) or the. like, or the mixtures of any of the foregoing. Said process may hence be conducted either continuously or intermittently; and obviously the primary and secondary furnaces may if desired, beentirely separate and 5 distinct from each other. e

7 With reference to-the term nascent as applied to alkali metals in the appended claims, I desire topoint out that it is barely possible -that a freshly deposited or freed metal of this class may notbe in exactly the condition to which this term'is generally ap plied (as to nitrogen, for example); but such metals are at. the moment of liberation, and possibly for a short while thereafter,- more active chemically than at other times,

'and hence this'term is applied to said metals compounds, which comprises electrolytically depositing an alkali.v metal and effecting a direct reaction between such metal, While in tween an alkali metal in thenascent state and a gaseous nitrogenous compound assomated with a carbonaceous substance.

3. The process of producing cyanogen compounds which comprises eflecting a direct reaction in a mass ofmolten cyanogen compounds, between an alkali metal in the nascent :state and a nitrogenous reagent assomated with a carbonaceous substance, said reagent including hydrogen as one of the constituents thereof, and the said mass being free from water and water forming constituents.

- nitrogen,

salt.

4. The process of producing an alkalimetal cyanogen compound which comprises 25' directl reacting with 'trimethylamin on electro yt-icallydeposited, nascent alkali metal at the instant of its deposition from, and while within, a bath of fusedcyanogen 5. The. process. of producing cyanogen compounds which involves reacting on an electrolytically deposited metal with a hydrocarbon-nitrogen compound .while said metal is still in the nascent state due to its electrolytic deposition.

6.'The process of producing cyanogen compounds which involves reacting. on an electrolytically deposited metal with a hy drogen carbon-nitro en compound which is free from oxygen wfiile said metal is still in the nascent state due to its electrolytic deposition.

7. The process of compounds which comprises reacting on a metal whilein-thenascent state with a hydrogen-carbon-nitrogen, compound which is free from oxygen and with a supplementary nitrogenous reagent. 8. The process of producing cyanogen .compounds'which comprises effecting a direct reaction between a metal while in the nascent.state, 'carbon and nitrogen, both of said last mentioned elements being also nascent at the instantof such reaction while excluding oxygen from the vicinity of suchreaction.

9. The process of producing c anogen compounds which comprises electro ytically depositing an alkali metal by a direct electric current, and efiecting a direct reaction between the state at theinstant of such-reaction.

producing cyanogen temperature substantially exceeding so deposited metal, carbon and the latter element-and the metal,

being in the nascent" metal while compounds, which comprises electrolytically depositing an alkali nietal from a mass of molten salt, and immediately and directly reacting on the so deposited metal with gaseous nitrogenous and carbonaceous reagents. to form the product sought.

11; The process of producing cyanogen compounds, which compriseselectrolytically ,clepositing an alkali metal from a mass of molten salt by passing a direct current through said salt from a mass of alloy comprising said alkali metal, and directly reacting on the so deposited metal with areagent other than the said salt, to form the product-sought by a single reaction.

'12. The process of producing cyanogen compounds,which comprises reacting on a metal while in the nascent state by passing a stream of aseous nitrogenous reagent over a surface 0t such metal in the presence of a carbonaceous reagent, said stream being maintained in intimate contact with said surface until substantially all of the moleoules of the nitrogenous reagent have been involved in'the reaction.

13. .The process of producing cyanogen compounds, which comprises reacting on a metal while in the nascent state by passing a stream of gaseous carbonaceous reagent over a surface of such metal in the presence of a nitrogenous reagent,said stream being-maintained in intimate contact with said. surface until substantially all of the molecules of the carbonaceous reagent have been'involved in the re'action.-

'14. The, .process of producing cyanogen compounds, whichcomprises reacting'on an electrolytically deposited metal by passing a stream of aseous reagent over a surface of such meta said reagent comprising both carbon and nitrogen. '15. The process of producing cyanogen compounds, which comprises directly reacting on an electrolytically deposited metal with. a non-salt nitrogenous compound associated with a carbonaceous substance, ath a t e melting point of sodium in a mass of molten material.

16. The process of producing cyanogen compounds, which comprises directly reacting on an electrolytically deposited metal wlth a non-salt carbonaceous compound assooiatedwith a nitrogenous substance, in a mass of molten material.

17. The compounds, which comprises directly reacting on an' electrolytically deposited metal with a gaseous carbonaceous compound associated with a nitrogenous substance, in a mass of molten materiaL.

' 18. The process of producing cyanogen compounds,

cyanid an said metal is in the nascent state with a non-salt compound compri ing carprocess of producing cyanogen which comprises reacting. on a said alkali metal out of said alloy, and d1- ing point of t the temperature at which the loy .metal, electrolytically depositing said light vproduct sought, the temperature at which bon and nitrogen, in a mass of molten material, to thereby immediately form a cyanogen compound. v v

19. The process of producing cyanogen compounds, which comprises formingan alloy of'an inert metal and an alkali metal at a temperature exceeding the melting point of sodium cyanid, electrolytically depositing the reaction occurs being substantially that at Which the alloy is formed. I

21. The process of producing cyanogen compounds, which comprises forming an alloy of an inert metal and a relatively light metal at a temperature exceeding the meltsodium cyanid, electrolytically depositing said light metal out of said. alloy, 1

and reacting on the so deposited metal with trimethylamin to'form the product sought, reaction occurs being substantially that at which the alloy 5 is formed. Y I

22. The process of producing cyanogen compounds, which comprises forming an alof an inert metal and a relatively light five eents Washington, D. C.

metal out of said alloy, and reacting 0p the so deposited metal with trimethylamln to form the product sought.

23. The process of producing an alkalimetal cyanogen compound which comprises directly reacting with a hydrocarbon amin on electrolytically-deposited, nascent alkalimetal, at the instant of its deposition from, and while within,.a bath of fused nitrogenous salt.

24. The process of producing cyanogen compounds which comprises reacting on a metal while in the nascent state with a hydrocarbon-nitrogen compound and a supplementary nitrogenous reagent.

25. The process of producing cyanogen compounds which comprisesreacting on a metal while in the nascent state with a hydrocarbon-nitrogen compound and a supplementary reagent, one constituent element of which is a constituent element of the said hydrocarbon-nitrogen compound. v

26. The process of producing cyanogen compounds which involves reacting on a metal capable of acting as the base of a cyanogen'compound, and while said metal is in the nascent state, nitrogen compound, portions of whose carbonaceous and nitrogenous constituents are capable of combining to form a radical comprising carbon and nitrogen, compound is reacted upon by said nascent metal.

In witness whereof, I subscribe my signature, in the presence of two witnesses.

CHARLES E. ACKER.

Witnesses:

lVALoo M, CHAPIN, WILLIAM C. LARY.

each, by addressing the Commissioner of Patents,

when the said p with. a hydrogen-carbonv 

